Mechanism for forming a helically wound tube



Aug. 9, 1955 J. E. FAY 2,714,854

MECHANISM FOR FORMING A HELICALLY WOUND TUBE Original Filed A ril 23,1948 1'10. 4. M .F'IEJ IN V EN TOR. Jan 1E5 E. E4):

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United States Patent MECHANISM FOR FORMING A HELICALLY WOUND TUBE JamesE. Fay, Middletown, Ohio, assiguor to Armco Steel Corporation,Middletown, Ohio, a corporation of Ohio Original application April 23,1948, Serial No. 22,786,

. now Patent No. 2,649,888, dated August 25, 1953. Di-

vided and this application November 30, 1951, Serial No. 259,041

2 Claims. (Cl. 113-35) This invention relates to a mechanism forcorrugating strips of material and forming the same into tubes.

This application is a division of my copending application Serial No.22,786, filed April 23, 1948, now Patent No. 2,649,888. That applicationcontains a full disclosure of the corrugating mechanism, and claimscovering said mechanism. The corrugating mechanism, will therefore notbe described herein, except as may be necessary to an understanding ofthe tube forming mechanism. 6

One object of the invention is to provide the tube forming mechanismwith means for moving the adjacent edges of the spiral strip to relativepositions in which they may be united one with the other.

A further object of the invention is to provide a combined corrugatingmechanism and tube forming mechanism with means interposed between saidmechanisms for perforating the corrugated strip Other objects of theinvention may appear as the mechanism is described in detail.

In the accompanying drawing,

Figure 1 is a plan view of a tube forming mechanism showing thedischarge end of the corrugating mechanism of my said copendingapplication.

Figure 2 is a cross sectional view taken on the line 2--2 of Figure 1;

Figure 3 is a detail view of the chain clamping device, I

showing the chain in section.

Figure 4 is a cross sectional view taken on the line 44 of Figure 1.

Figure 5 is a cross sectional view taken on the line 5-5 of Figure 1.

Corrugated strips or sheets are frequently utilized in the manufactureof spirally wound tubing and I have disclosed in the present applicationa tube forming device which receives the corrugated sheet directly fromthe corrugating mechanism (which may be the mechanism of my saidcopending case), winds the same into a spiral tube and welds the jointsof the tube. As shown in Figs. 1 to 4 this device comprises a mandrel 65extending obliquely to the path of the corrugated sheet 66 as the latterpasses beyond the feeding out rolls 31 of the corrugating mechanism. Themandrel is rigidly supported at one end only, as by an upright standard67, at one side of the path of said strip of material, and the other endof the mandrel extends beyond the other side of the strip 66 and isunsupported and unobstructed so that the strip may be wound about thesame to form the tube. A supporting member or bracket 68 is mounted atthat side of the path of said strip which is adjacent the standard 67and extends inwardly above the strip, in the present instance to aposition above the apex of that corrugation which is adjacent themandrel support, as shown at 69. Supported by this bracket 68 arevertically spaced guide members 70 and 71 arranged to receive the strip66 between them. A flexible guide element, such as a chain 72, isconnected at one end with a fixed support above the mandrel and nearthat edge of the strip adjacent 2,714,864 Patented Aug. 9,

the mandrel support, in the present instance the chain'is anchored onthe forward edge of the upper guide member 70 and extends forwardly anddownwardly therefrom to a position a substantial distance below themandrel, and then laterally and rearwardly toward the other side of thestrip and then upwardly and forwardly and this end of the chain isfirmly anchored in a position beyond and spaced from that edge of thepath of the strip 66 whichis adjacent the unobstructed end of themandrel. Preferably the last mentioned end of the chain, while rigidlyanchored, is adjustable lengthwise of the path of the strip. In thepresent instance the end of the chain. is secured to a screw threadedmember 73 which extends through an apertured lug 74 on a fixed standard75 and is retained thereon by a nut 76. As the corrugated strip movesforwardly it passes beyond the guide members 70 and 71 and engages thedownwardly extending part of the chain 72 which deflects the samedownwardly and laterally and causes that edge portion thereof which isengaged by the chain to follow the chain and to be thus wound spirallyabout the mandrel 65. In the present instance the links of the chain 72have mounted between them a series of rollers 77, the rollers having aperipheral shape corresponding approximately to the apex portion of thecorrugation and adapted to receive the latter. Thus as the strip isforced along the chain, by the feeding rolls31, the apex 69 of thecorrugation, or other part of the edge portion of the strip which is incontact with the chain, is caused to follow the chain so that theadjacent edge of the strip, as it turns about the mandrel, is at alltimes spaced a uniform distance from the chain and as a spiralconvolution of the strip approaches completion that edge thereof whichwas originally adjacent the mandrel support 67 is moved to a positionbeyond the opposite edge of a succeeding portion of the strip andextends along the close to the last mentioned edge so as to form asection of a spiral tube. A guide roller 78 mounted on a fixed butadjustable support 79 bears against the downwardly extending portion ofthe apex of a corrugation adjacent that edge of the strip opposite themandrel support and thus causes that edge portion, of the strip to movein proper relation to the first mentioned edge portion thereof. Theintermediate portion of the chain 72 is anchored to a fixed supportarranged below the mandrel to retain the chain positively in a positionto impart the proper initial spiral movement to the strip, the point atwhich the chain is anchored depending in part at least upon the diameterof the tube which is to be formed. The chain may be anchored in anysuitable way but in the present instance there is mounted on a fixedsupport below the mandrel a clamping device comprising relativelymovable parts 80 adapted to receive a pair of links of the chain 72between them and to be clamped tightly against the same by a bolt 81.There is usually more or less camber in a strip of material of this kindand as a result the adjacent edges of the spirally wound portion of thestrip and of that portion thereof which has not yet been wound are notuniformly spaced one from the other and are likely to be so displacedwith relation one to the other that it is not possible to unite thesame, by welding or otherwise, so as to form a continuous tube. I havetherefore provided a device by which the adjacent edges may bemaintained in such relative positions that they can be united. As shownin Fig. 4 the device comprises two pairs of rollers engagingrespectively the edge portion of the body of the strip 66 and of thespiral portion of the strip, as shown at 660. Each pair of rollersincludes a lower roller 82 pressed upwardly against the edge portion ofone part of the strip by a spring 83 and an upper roller 84 engaging theupper surface of the edge portion of the strip 66 and adjustablyconnected with a fixed support, such as a laterally extending portion ofthe standard 75. In the present instance the rollers 84 are rotatablyconnected with yokes having screw threaded shanks 85 to extend throughopenings in the standard 75 and are movable vertically with relation tothe latter by nuts 86 and 87 mounted thereon. Thus by adjusting therollers in accordance with variations in the camber of the strip theadjacent edge portions thereof can be maintained in such positions thatthey may be united by welding. The welding may be effected in anysuitable manner, as by an electric welding mechanism including anelectrode 88, and the welding may be continuous so that the completedtube moves lengthwise beyond the end of the mandrel and may be severedinto lengths as desired.

It is often desirable that spiral tubing of this type shall be providedwith perforations in at least one side thereof to permit drainage.Heretofore such perforations have been formed in the finished pipe ortubing and that procedure is slow and expensive. In the presentmechanism I have provided means whereby the perforations may be formedin the corrugated strip as it passed from the corrugating mechanism tothe tube forming mechanism in the manner that involves very littleexpense. For that purpose I have provided a series of cutting devicesspaced across the width of the strip and adapted to form perforationstherein at longitudinally spaced intervals. As here shown each devicecomprises an upper rotatable member 89 and a lower rotatable member 90,the members being mounted respectively on shafts 91 and 92 which may bedriven from any suitable source of power such as the source from whichthe feeding out rolls 31 are driven. The upper member 89 is providedwith a circumferential groove 93 and the lower member is provided with aplurality of radially extending cutting elements or fingers 94 of anaxial width just slightly less than the width of the groove 93 in themember 89. As the corrugated strip 66 moves between the members 89 and90 the member 89 rolls on the surface thereof and the perforatingfingers 94 of the member 90 will successively engage the lower surfaceof the strip in line with the groove 93 and slit the material of thestrip on the lines of contact of each finger with the strip along theside walls of the groove 93 and as the severing action continues thefinger forces that part of the strip which lies between the slits intothe groove such a distance that it will be spaced from the surface ofthe strip and will thus permit the passage of liquid through theperforations, but will tend to prevent the clogging of the aperture.

While I have shown and described one embodiment of my invention I wishit to be understood that I do not desire to be limited to the detailsthereof as various modifications thereof may occur to a person skilledin the art.

Having now fully described my invention what I claim as new and desireto secure by Letters Patent is:

1. In a mechanism for forming helically wound tubes, means for moving acorrugated strip of material in a predetermined planar path, anundersize bending mandrel disposed at an angle to the axis of said path,said mandrel being rigidly supported at one end and free at its otherend, a first fixed supporting means above said mandrel and above saidstrip adjacent an edge thereof, a second fixed supporting meanssimilarly positioned at a point axially displaced along said mandreltoward its free end by a distance corresponding to the pitch of thehelix, a chain secured at one end to said first fixed supporting means,extending helically around said mandrel and spaced therefrom, andadjustably secured to said second fixed supporting means, fixed groovedmeans slidingly engaging saidchain at the bottom of the helix to holdthe same against lateral movement, a buttress roll arranged to bearagainst the outside of the strip at a point substantially 90 in rotationfrom the beginning of the helix and adjacent the edge of the stripopposite the said chain.

2. The structure of claim 1, wherein a welding instrumentality issecured to said second fixed supporting means, said weldinginstrumentality performing a helical weld as the strip is formed into atube.

References Cited in the file of this patent ili' 'UNlTED STATES PATENTS375,435} Alden Dec. 27, 1887 1,939,581; Tesmer Dec. 12, 1933 1,968,365Bailey July 31, 1934 1,976,686 Wunderlich Oct. 9, 1934 2,185,337; GreenJan. 2, 1940 2,237,309}, McMinn Apr. 8, 1941 FOREIGN PATENTS 482,413Great Britain Mar. 29, 1938

